Ucres, qq-s-763 class 416 per united aircraft corporation specification no. Hs178, rockwell hardness rating rs75-79.5, trinangular shape, 0.480 in. Min, 0.520 in. Max width, 0.290 in. Min, 0.320 in. Max lg, two holes, drill, 0.160 in. Diameter on 0.750 in. Centers